The general design of present disc drives provides users with several methods to insert a disc into a drive. The most popular method for disc drives is using an extendible tray to load a disc into the drive. The tray is slidably movably connected to the housing of the disc drive through tracks. Electronic control and a motor are usually used to control the ejection and withdrawal of a tray. When a user manipulates controls to eject a tray, the motor operates to move the tray to the end of the tracks. As for the drives in laptops, the motor operates to control the engagement status between the tray and the housing; then, a part of the tray is ejected out of the housing by the ejection device with springs. After that, a user may manually draw the tray to the end of the tracks to make the tray completely exposed.
However, the disc drive with this kind of tray usually has certain common problems. The tray cannot be ejected out of the drive when power supply is interrupted or when the computer is turned off. To take the disc out of the drive, a user must reboot the computer or turn on the computer again. The same condition also occurs when the computer is not functioning in a normal way or when it is shut down unexpectedly.
To deal with this problem, the present disc drives with disc trays all have an emergency ejection device. A typical design of an emergency ejection device is to have a hole on the panel of a drive. When the device comes to a situation that the tray must be urgently ejected, the user may use a pin to trigger the inner emergency ejection device through the little hole to eject the tray out of the drive.